The present invention relates to a heat resistant material, and to the making of articles which are at least partially formed of the heat resistant material.
The casting of metal articles using sand molds and sand cores is well known in the art. A sand mold can be made from a mixture of sand and an organic binder by packing the mixture loosely or tightly around a pattern. The pattern is then removed, leaving a cavity in the sand that replicates the shape of the pattern. Once the organic binder is shape-stabilized by a curing technique, the cavity in the mold is filled with a molten metal by pouring the molten metal into the mold.
Sand mold cores can be made by placing a sand and binder mixture into a core box. There, the sand and binder mixture takes the shape of the cavity in the box, becomes hard, and is removed. After the mold is made, the core is then set in the mold. Molten metal is poured in the mold and fills the mold except where the sand core is present.
The binder materials used in making the sand molds, and sand cores can include inorganic binders, organic binders, and organometallic binders. Oraganometallic binders are uniquely suited for use as binders for sand molds and sand cores because they provide strength to the sand molds and sand cores at extremely low binder levels. Additionally, organometallic binders can be used to bind particles together to make shapes directly.
U.S. Pat. No. 5,884,688 discloses a method of fabricating shaped bodies such as negatives of parts to be made, as well as, shapes directly. The method comprises coating sand with liquid organic-metallic binder, forming a shape from said binder mixture, and hardening said binder mixture to form the shaped body. One organometallic binder is a polyureasilazane.
U.S. Pat. No. 5,552,466 discloses a method of producing an article with high temperature and thermal shock resistance comprising forming a blend of at least one lower viscosity silicone polymer. The blend is disclosed as being xe2x80x9ccermitizablexe2x80x9d at a temperature above about 1100xc2x0 F. (590xc2x0 C.). An article, formed in accordance with the patent, contains a layer of material formed from a silicone blend.
The present invention relates to particulate material and method for forming a heat resistant composite. A particulate silicone based material is provided. The particulate silicone based material is heated to a temperature between about 200xc2x0 F. and 400xc2x0 F. The particulate silicone based material is cooled until a solid composite is formed. The solid composite is resistant to melting and thermal decomposition when heated to temperatures of at least about 3000xc2x0 F. The particulate silicone based material may be formed by mixing liquid silicone resin with a catalyst and powdered silicone molding compound. The result may be a particulate which appears to be dry.
It should be understood that the silicone based material of the present invention has many different uses. For example, the silicone based material of the present invention may be used to form a core or mold which is used in forming other articles. Alternatively, the silicone based material may be used to form an article itself. As another alternative, the silicone based material may be used as a covering. It is contemplated that the silicone based material of the present invention may be used in many different ways in addition to the specific ways described herein.